diff --git a/src/main/java/org/apache/ibatis/migration/MigrationReader.java b/src/main/java/org/apache/ibatis/migration/MigrationReader.java
index 76260dde..c803f849 100644
--- a/src/main/java/org/apache/ibatis/migration/MigrationReader.java
+++ b/src/main/java/org/apache/ibatis/migration/MigrationReader.java
@@ -95,7 +95,7 @@ public int read(char[] cbuf, int off, int len) throws IOException {
     while (buffer.length() == 0) {
       int result = in.read(cbuf, off, len);
       if (result == -1) {
-        if (lineBuffer.length() > 0 && !undo && !inUndo) {
+        if (lineBuffer.length() > 0 && (!undo || inUndo)) {
           buffer.append(lineBuffer).append(lineSeparator);
           lineBuffer.setLength(0);
         }
diff --git a/src/test/java/org/apache/ibatis/migration/MigrationReaderTest.java b/src/test/java/org/apache/ibatis/migration/MigrationReaderTest.java
index 985f5fba..2025f2ee 100644
--- a/src/test/java/org/apache/ibatis/migration/MigrationReaderTest.java
+++ b/src/test/java/org/apache/ibatis/migration/MigrationReaderTest.java
@@ -72,6 +72,19 @@ public void shouldReturnUndoPart() throws Exception {
     // @formatter:on
   }
 
+  @Test
+  public void shouldReturnUndoPart_NoEndBreak() throws Exception {
+    // @formatter:off
+    String script = "-- comment\n"
+        + "do part\n"
+        + "--//@UNDO\n"
+        + "undo part";
+    String result = readAsString(new MigrationReader(strToInputStream(script, charset), charset, true, null));
+    assertEquals("-- @UNDO\n"
+        + "undo part\n", result);
+    // @formatter:on
+  }
+
   @Test
   public void shouldUndoCommentBeLenient() throws Exception {
     // @formatter:off